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WHAT IS
DYSTONIA?
Dystonia is the
third most common movement disorder in the world after Tremor and
Parkinson's Disease. It is the name
given to a group of movement disorders which are characterised by
sustained muscle contractions causing twisting and repetitive
movements or abnormal postures. Such dystonic spasms may affect one
or more parts of the body, or the whole body. They are frequently
painful, but disappear in sleep. Dystonias are often misunderstood
by the public and may be misdiagnosed by medical professionals not
familiar with the condition. Symptoms are often
transient and can be mistaken for emotional or psychiatric
disorders. Intellect, personality,
emotions, sight, hearing, sensation and sexual function may be quite
normal, but may be inhibited by the affliction.
WHAT
CAUSES DYSTONIA?
The cause of these abnormal movements is
thought to stem from the basal ganglia area of the brain which
controls muscle activity.
GENERALISED DYSTONIA
This type
usually starts in one part of the body, usually in a foot or a leg.
After walking or other exercise, the foot may turn under, so that
the person walks on the outer edge of the foot. It usually starts in
childhood. It often spreads to other parts of the body, including
the back, neck and arm. It can be inherited and is occasionally
sporadic.
FOCAL DYSTONIAS
Blepharospasm
is a focal dystonia of the muscles around the eye. Early symptoms
may be uncontrolled blinking, especially in bright sunlight. In some
cases, only one eye is affected initially, but in time, both eyes
close. The spasms may render the person functionally blind, although
the eyes and vision remain normal.
Oro-mandibular Dystonia
is a focal dystonia of the jaw, tongue and mouth. Speech and
swallowing may be affected.
Meige’s Syndrome
combines Blepharospasm and Oromandibular Dystonia, and is also known
an Brueghel’s Syndrome, after the 16th century artist who
painted patients with the condition.
Laryngeal Dystonia
is a focal dystonia of the
speech muscles which causes strained, forced speech, or an inability
to speak in more than a whisper.
Spasmodic Torticollis
is a focal dystonia of the neck. It causes twisting or jerking of
the neck which may result in forcing the head nearly parallel with
the shoulders.
Writers’ cramp,
typists’ cramp, pianists’ cramp and golfers' cramp are focal dystonias of the hand or forearm.
Hemi-facial spasm
is a chronic twitching or spasm of one side of the face.
Strabismus is not
technically a dystonia, but as a muscular disorder causing the eyes
to be "out of alignment", may be responsive to treatments similar to
those used for true dystonias.
DIAGNOSING DYSTONIA
Dystonias
can be very difficult to diagnose. Early signs
are generalised and often regarded as nervous "tics". As a general
rule, diagnosis depends on careful clinical observation rather than
a laboratory study. Dystonia symptoms vary with change of posture,
worsen with stress, decrease with relaxation or hypnosis, and disappear with
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